Aero Design Senior Project Community Ideas

[kach22i]

Originally Posted by freebeard

Maybe we should have the mods carve this off into another thread and let the OP (should he return) have his thread back.........

I think he probably got out of it more than he could have wanted. Cashed out fresh with ideas and a new perspective, ready to annoy his teacher with all of his youthful enthusiasm. I hope he gets an "A".

The forum has been a bit slow as of late, this thread provided an opportunity to spice things up and revisit some simmering thoughts. Old guys need that sort of thing once in a while, right? A casual corner as it were.

Revised topic: If I had a wind tunnel, this is what I would test.

[kach22i]

Originally Posted by Xist

Should roof boxes follow an extended template?

I've never seen anyone show this before.

We have seen camper tops on pickup trucks, which I suppose are similar.

A good use of a wind tunnel in this situation would be to test this layout verses one where the storage box was shaped like a canopy/blister.

1. Overall template form approach to be tested (more of an arc/crown)

2. Near surface blister/canopy to be tested (more of teardrop).

I say this would be a good use of a wind tunnel.

I would call such an item a Caraway Carryall. Because it most likely would look like a caraway seed.

Irish Soda Bread - The Creekside Cook

But first – let us admire the lovely caraway seed, with it’s symmetrical little stripes. They’ve always looked like tiny bananas to me.

Something about the shape of these seeds drives the human imagination.

[kach22i]

From back in 2011.....................

Mulsanne's Corner: Race Car Engineering Le Mans 2011

First seen at the 2011 Le Mans test day, Oak Racing have hit upon a clever design execution that maneuvers around the gurney regulation. Ultimately the concept is a regulatory work around and nothing more, though more on the specifics in a moment. But getting to this conclusion was fraught at first. Initially it was suggested that the protuberances were designed with pure aerodynamics in mind; discussions were rampant about the bumps acting as vortex generators. There was even mention the bumps were utilizing an aerodynamic concept seen in nature and on of all things, whales. Yes, the giant mammal kind.

Apparently scientists have always been puzzled about whale’s agility given their size. And when researched, they took note of bumps on the leading edge of whale fins. They came to the conclusion the bumps help reduce span wise leading edge flow migration and locally better organized the water flow leading to a much more efficient fin (or wing). Hey, don’t shoot the messenger, I’m just repeating what I read.................

...........alternating gurney angle reduction.

Go to the Mulsanne's Corner link above to read more.

First found the image and link here: (related discussion took place)
Micro Vortex Generators to decrease flow separation on high camber wings - Nissan Road Racing Forums

Ignore the bumps/domes for a minute, the trailing edge is not only wavy but appears to be fluted or corrugated as in the earliest concepts I posted in this thread.

Overall the Mulsanne's Corner post does an excellent job of explaining all the reach-a-rounds the race teams do in order to circumvent the rules.

[freebeard]

The caraway seeds remind me of pine needles. They worm themselves in everywhere; behind the side trim, down the ventilator...

I was re-watching Dune and a scene in a throne room. The crenellations in the background got me wondering...


http://dunepedia.wikifoundry.com/page/Shaddam+Corrino+IV

How would you scallop a sheet of corrugated metal? My first though is drill holes in the bottom of the corrugations, cut somewhere around the edge of the holes and the nip off the 'ears' to make a scallop.

[Aeroguy]

I would think you could stamp the scallops into it. I don't know why you'd use corrugated metal instead of sheet metal.

[kach22i]

Originally Posted by Aeroguy

I would think you could stamp the scallops into it. I don't know why you'd use corrugated metal instead of sheet metal.

The corrugated metal image was just one of many examples or variants within the same conceptual family.

Testing flat sheets with waves, wavy sheets with waves, and more complex 3D shapes similar to the big black whale foil and orange blade are all game.

There is no one design favored over another without objective testing for proof of concept.

There must be a million designs which could be generated based on the same principals, best not to grow a predetermined bias, let the wind tunnel do that for you.

Aerodynamics by George Kachadoorian | Photobucket


A 3D printer or CNC milling machine opens up a world of possibilities as long as you have the power of human imagination on your side.

If you don't have these tools and the computer programs which go with them, then good old fashion plasticine modeling clay or a soft workable wood can be used. I'm not a big fan of sanding foam, the static cling and mess is not missed.

EDIT: Tested in real life and works as intended, flat sheet with curl at end, curled end cut with waves in it.

George Kachadoorian's Library | Photobucket


Use what you have on hand.

I've used this same process of experimenting with loudspeakers, had some fun with whizzer designs to extend the high end frequency response of a driver. I just used my ears as a measuring device, more accurate than a microphone and computer program in my opinion. The human ear is an amazing instrument once trained.

Can you turn a woofer into a full range driver?
http://www.diyaudio.com/forums/full-...-driver-2.html


I found that I could extend the frequency, but at the expense of lowering dynamic response. In other words, the whizzer mass slowed down the speaker and made it lazy sounding.

However I considered it a good learning experience.

Best thing I found was actually stiffening the dust cap with tiny glass beads glued to it. Not the diamond dust encrusted tweeter of the big guys (a real thing, not the Frank Zappa song), but pretty darn close considering the low tech involved.

[freebeard]

I would think you could stamp the scallops into it. I don't know why you'd use corrugated metal instead of sheet metal.

Because when I replace the sunshade on my abode with a solar collector I will have a lot of corrugated metal. And it sounds easier to scallop corrugated than corrugate scallops flat sheets.

And I'd hammer-form the edge of the scallop to stiffen it. I'm thinking about columns in my throne room, not a spoiler.

[aerohead]

here's the original 911/912

later,with whale-tail

The Panamera corrects the high-lift roofline

Trying to correct rear lift with wing

Getting away from the Lange roof

Blasphemy!

918 Spyder loses Lange profile altogether

[kach22i]

Originally Posted by aerohead

Getting away from the Lange roof...............

918 Spyder loses Lange profile altogether

I had to look Lange up, been a long time since I read that name, but recall the images.

http://ecomodder.com/forum/showthrea...e-33673-6.html

Originally Posted by aerohead

I think that this is the Lange car which inspired the early Porsche sports cars,like the 60K10 which Ferdinand drove between Stuttgart and Berlin before the war.

To the Cd 0.14-16 featureless,smooth model,we'd have to add in all the features drag,interference drag,drag due to lift,cooling system drag,etc..
Also,if you look at the Lange car in plan view,it has extreme plan taper,nearly from the front of the car.Never done in the production cars.


The Volkhart Sagitta V2 is very similar to the Lange body.Cd 0.21.

[freebeard]

I had to look up blasphemy, here was the picture:


Jim Meyer Racing Products - BLASPHEMI